<h2>DESCRIPTION</h2>

<em>t.rast.contour</em> is designed to produce a space time vector dataset of 
specified contours from a space time raster dataset. This module works as a front-end to
<a href="r.contour.html">r.contour</a> and therefore supports all parameter
of this module. Hence, all raster map layers in a space time raster dataset
are successively passed to <a href="r.contour.html">r.contour</a> that computes 
the contour lines. 
Please refer to the <a href="r.contour.html">r.contour</a> documentation 
for a detailed description.
The new generated vector contour map
layers will be registered in the output space time vector dataset, using 
the same time stamps as their raster map layer origins.
<p>
This module supports the parallel processing of <a href="r.contour.html">r.contour</a>
module instances. The number of parallel processes 
can be set with the <em>nprocs</em> option. 
However, this will only work in conjunction with the <em>-t</em>
flag, that avoids the creation of attribute tables. 
The parallel creation of attribute tables is not supported.
<p>
The <em>where</em> option allows selecting subsets of the input space time raster
dataset.
<p>
The flag <em>-n</em> can be used to force the registration of empty 
vector map layers. Empty vector maps may occur in case that empty 
raster map layers should be converted into vector map layers, or in case the
chosen steps or contour levels are not present in the raster map layers.

<h2>SEE ALSO</h2>

<em>
<a href="r.contour.html">r.contour</a>,
<a href="t.vect.db.select.html">t.rast.db.select</a>,
<a href="t.info.html">t.info</a>
</em>


<h2>AUTHOR</h2>

S&ouml;ren Gebbert, Geoinformatikb&uuml;ro Dassau

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